Metabolic and Physiological Changes During Minor Orthopaedic Surgery in Otherwise Healthy Patients

NCT03450746 | Completed

• 1 other identifier: AAUH-ANAESTH-03
• Study Type: observational
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

The air we breathe contains 21% of oxygen. Oxygen is vital for the cells ability to produce energy and without it we could not survive. Oxygen normally exists as a molecule consisting of two atoms, O2. It has two unpaired electrons and thus is unstable and willing to accept electrons to become stable. During the formation of ATP a transportation of electrons happens over the inner membrane of the mitochondria's. Oxygen can accept these and is thereby reduced to water. Normally about 4% is not fully reduced and instead produces superoxide. Superoxide is transformed to hydrogen peroxide by superoxide dismutase (SOD) and then into oxygen and water by catalase and glutathione peroxidase. It is also possible for hydrogen peroxide to be converted to hydroxyl radicals by Fenton reactions. All these radicals are called reactive oxygen species (ROS) and they are highly reactive and capable to induce damage to cellular components as proteins, DNA and lipids. Under normal conditions SOD, catalase and glutathione peroxidase work as anti-oxidative compounds to prevent oxidative stress and damage. However, under hyperoxic conditions these defences can be overwhelmed, resulting in the formation of excess ROS and thus oxidative damage. During general anaesthesia the use of supplemental oxygen to avoid life-threatening hypoxaemia has been common practice for many years and a fixed fraction of inspired oxygen (FiO2) ranging from 0.3 to 1.0 is often used. This lead to supranormal levels of oxygen in the lungs and most of the patients also have supranormal levels of partial pressure of arterial oxygen in their blood. This study will examine otherwise healthy ambulant patients undergoing minor orthopaedic surgery during general anaesthesia to elucidate metabolic and physiological changes caused by ventilation with FiO2 0.50 for at least 45 minutes using standard respiratory settings. Exhaled breath condensate (EBC) and arterial blood will be collected prior to and after surgery. The two EBCs and two blood samples will be stored at -80°C for analysis after all patients have been included. The metabolic changes will be measured with NMR technique and multivariate statistical analysis comparing baseline values with values obtained after oxygen exposure. Collapse of the small airways induced by anaesthesia and FiO2 will be evaluated by measuring resistance and reactance with airway oscillometry after surgery compared to a baseline measurement before surgery.

Conditions

Metabolomics; Anesthesia, General; Oxygen

Outcome Measures

Primary Outcomes (1)

• Metabolites in exhaled breath condensate and in arterial blood

  Metabolites measured by Nuclear Magnetic Resonance spectroscopy (NMR), explanatory study thus every changes in metabolites will be visualized

  minor surgery (approximately 45-120 minutes)

Secondary Outcomes (6)

• Minor airway resistance

  minor surgery (approximately 45-120 minutes)

• Airway reactance

  minor surgery (approximately 45-120 minutes)

• Mean arterial bloodpressure

  minor surgery (approximately 45-120 minutes)

• heart rate

  minor surgery (approximately 45-120 minutes)

• oxygen saturation

  minor surgery (approximately 45-120 minutes)

Study Arms (1)

Healthy patients for orthopaedic surgery

Standard general anaesthesia and ventilation with FiO2 0.50 for at least 45 minutes following the standard settings in our department.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Subjects are recruited at Aalborg University Hospital in Denmark among patients scheduled for ambulant minor orthopedic surgery expected to last at least 45 minutes.

You may qualify if:

• Over the age of 18 years
• Otherwise healthy (No major illness and not taking any medicine on a regular basis)
• Non-smoker (Have never smoked or stopped smoking two years or more before the trial date)
• Have given informed consent

You may not qualify if:

• Any respiratory infection in the past three months leading to consulting a doctor (Any infection in the lungs or the airways in the three months leading up to the trial that resulted in the participant consulting a doctor or taking any medication for the infection)
• Any alcohol intake the last 24 hours (Drinking any alcohol in the last 24 hours up to the start of the trial)
• Pregnancy (Confirmed by positive urine human gonadotropin (hCG) or plasma-hCG)

Sponsors & Collaborators

• Aalborg University Hospital: lead

Study Sites (1)

Departmen of Anaesthesia and Intensive Care Medicine, Aalborg University Hospital

Aalborg, 9000, Denmark

Location

Biospecimen

Retention: SAMPLES WITHOUT DNA

Exhaled breath condensate and arterial blood for matabolomic analysis.

Study Officials

• Bodil S Rasmussen, Professor

  Department of Anaesthesia and Intensive Care Medicine, Aalborg University Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: December 22, 2017
• First Posted: March 1, 2018
• Study Start: November 2, 2017
• Primary Completion: November 22, 2017
• Study Completion: November 22, 2017
• Last Updated: June 9, 2020

Record last verified: 2020-06

Data Sharing

• IPD Sharing: Will not share

Locations

DK (1)